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To enable thorough scientific exploitation of the data, in LoTSS-DR2 a wide variety of different data products are being made publicly available with DOI:10.25606/SURF.LoTSS-DR2 and can be accessed via the LOFAR surveys webpage\footnote{\url{https://lofar-surveys.org/}}, the ASTRON Virtual Observatory\footnote{\url{https://vo.astron.nl}} and the SURF Data Repository\footnote{\url{https://repository.surfsara.nl/}}. More specifically, this data release includes the following Stokes I products:
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\begin{enumerate}[label=\textbf{Product.A\arabic*},ref=\textbf{Step.A\arabic*},leftmargin=1.9cm]
\item Mosaiced astrometric-corrected Stokes I 6$\arcsec$ resolution 120-168\,MHz restored images with associated \textsc{PyBDSF} residual and noise maps.
\item Mosaiced Stokes I 20$\arcsec$ resolution 120-168\,MHz restored images.
\item Individual Stokes I 6$\arcsec$ (with and without astrometric correction) and 20$\arcsec$ resolution 120-168\,MHz restored images with associated DDFacet model, residual and mask images.
\item Individual Stokes I 6$\arcsec$ (with astrometric correction) resolution 16\,MHz bandwidth images with central frequencies of 128, 144 and 160\,MHz.
\item Catalogue of 4,396,228 radio sources and the 5,121,366 Gaussian components that describe them (example entries are shown in Tab. 1).
\item Hierarchical Progressive Surveys (see \citealt{Fernique_2015}) images to visualise the mosaiced Stokes I 6$\arcsec$ and 20$\arcsec$ resolution images.
\end{enumerate}
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In addition, the following polarisation products are included in this data release:
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\begin{enumerate}[label=\textbf{Product.B\arabic*},ref=\textbf{Step.A\arabic*},leftmargin=1.9cm]
\item Individual observation Stokes QU 20$\arcsec$ resolution undeconvolved 480-plane image cubes with a frequency resolution of 97.6\,kHz.
\item Individual observation Stokes QU 4$\arcmin$ resolution undeconvolved 480-plane image cubes with a frequency resolution of 97.6\,kHz.
\item Individual observation Stokes V 20$\arcsec$ resolution 120-168\,MHZ continuum undeconvolved images.
\end{enumerate}
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And finally the following $uv$-data and calibration products are included for each pointing:
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\begin{enumerate}[label=\textbf{Product.C\arabic*},ref=\textbf{Step.A\arabic*},leftmargin=1.9cm]
\item DI calibrated visibilities and DD calibration solutions.
\item Facet layout and astrometric corrections
\end{enumerate}
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We emphasise that the released products do not incorporate the range of limitations that are described in Sect. \ref{sec:image_quality} as these can vary with aspects such as observing conditions and source properties and are not always applicable. For example, the catalogues and noise images contain only the \textsc{PyBDSF} statistical uncertainties from the source characterisation. The extensive variety of products do, however, allow for a robust assessment of the data and image accuracy and, together with the description in this publication, we hope that they can allow users to ascertain which, if any, limitations are appropriate to consider in any given study.

\begin{sidewaystable*}
\centering
{{Table 1:} An example of entries in the LoTSS-DR2 source catalogue which contains a total of 4,396,228 sources and is derived from 120-168\,MHz images (central frequency of 144\,MHz) with a resolution of 6$\arcsec$. The columns are: source identifier (ID), J2000 right ascension (RA), J2000 declination (Dec), peak brightness ($\rm{S_{P}}$), integrated flux density ($\rm{S_{I}}$), major axis (Maj), minor axis (Min), deconvolved major axis (DC Maj), deconvolved minor axis (DC Min), position angle (PA), local noise at the source location (RMS), type of source as classified by \textsc{PyBDSF} (Type -- here `S' indicates an isolated source fit with a single Gaussian; `C' represents sources fit by a single Gaussian but within an island of emission that contains other sources; and `M' is used for sources that are extended and fitted with multiple Gaussians), the mosaic identifier (Mosaic), the number of pointings that are mosaiced at the position of the source (Number pointings), and the primary beam attenuation weighted average of the deconvolution mask images at the source location (Masked fraction). The errors in the catalogue are the uncertainties obtained from the \textsc{PyBDSF} source fitting. Additional uncertainties on the source extensions, astrometry, flux density scale as well as descriptions of completeness, dynamic range and diffuse emission recovery limitations are described in Sect. \ref{sec:image_quality}. }\\

\label{tab:catalogue-example}
\begin{tabular}{lccccccccccccccc}
\hline
Source ID & RA & DEC & $S_{P}$ & $S_{I}$ & Maj & Min & DC\_Maj & DC\_Min & PA & RMS & Type & Mosaic & Number & Masked \\
& & & (mJy/ & (mJy) & ($\arcsec$) & ($\arcsec$) & ($\arcsec$) & ($\arcsec$)& ($^\circ$) & (mJy/ & & & pointings & fraction \\
& & & beam) & & & & & & & beam) \\ \hline
ILTJ075321.87 & 118.3411$^\circ$ & 27.9383$^\circ$ & 2.22 & 2.75 & 6.9 & 6.5 & 3.4 & 2.4 & 71 & 0.09 & S & P117+27 & 3 & 1.00 \\
+275617.7 & $\pm$0.1$\arcsec$ & $\pm$0.1$\arcsec$ & $\pm$0.09 & $\pm$0.19 & $\pm$0.3 & $\pm$0.3 & $\pm$0.3 & $\pm$0.3 & $\pm$28 \\
ILTJ133639.64 & 204.1652$^\circ$ & 52.8310$^\circ$ & 0.51 & 0.76 & 7.5 & 7.2 & 4.5 & 3.9 & 114 & 0.06 & S & P5Hetdex41 & 3 & 0.50 \\
+524951.5 & $\pm$0.4$\arcsec$ & $\pm$0.4$\arcsec$ & $\pm$0.06 & $\pm$0.15 & $\pm$1.0 & $\pm$0.9 & $\pm$1.0 & $\pm$0.9 & $\pm$115 \\
ILTJ105955.28 & 164.9803$^\circ$ & 55.0005$^\circ$ & 0.28 & 2.13 & 21.9 & 12.7 & 21.1 & 11.1 & 92 & 0.07 & S & P164+55 & 4 & 0.00 \\
+550001.9 & $\pm$2.1$\arcsec$ & $\pm$1.0$\arcsec$ & $\pm$0.06 & $\pm$0.50 & $\pm$4.9 & $\pm$2.5 & $\pm$4.9 & $\pm$2.5 & $\pm$24 \\
ILTJ105319.51 & 163.3313$^\circ$ & 45.7868$^\circ$ & 0.62 & 0.77 & 7.3 & 6.2 & 4.1 & 1.5 & 6 & 0.06 & S & P163+45 & 4 & 0.87 \\
+454712.5 & $\pm$0.3$\arcsec$ & $\pm$0.3$\arcsec$ & $\pm$0.07 & $\pm$0.13 & $\pm$0.8 & $\pm$0.6 & $\pm$0.8 & $\pm$0.6 & $\pm$29 \\
ILTJ125532.50 & 193.8854$^\circ$ & 45.0397$^\circ$ & 0.48 & 0.78 & 8.8 & 6.6 & 6.5 & 2.8 & 83 & 0.13 & S & P32Hetdex08 & 3 & 0.00 \\
+450223.0 & $\pm$1.2$\arcsec$ & $\pm$0.7$\arcsec$ & $\pm$0.13 & $\pm$0.33 & $\pm$2.7 & $\pm$1.6 & $\pm$2.7 & $\pm$1.6 & $\pm$45 \\
ILTJ085443.03 & 133.6793$^\circ$ & 46.2299$^\circ$ & 0.76 & 1.17 & 8.0 & 6.9 & 5.3 & 3.4 & 124 & 0.08 & S & P133+47 & 4 & 0.50 \\
+461347.4 & $\pm$0.4$\arcsec$ & $\pm$0.4$\arcsec$ & $\pm$0.09 & $\pm$0.21 & $\pm$1.0 & $\pm$0.8 & $\pm$1.0 & $\pm$0.8 & $\pm$34 \\
ILTJ022403.60 & 36.0150$^\circ$ & 30.0882$^\circ$ & 13.00 & 30.94 & 9.2 & 8.9 & 7.0 & 6.6 & 102 & 0.10 & M & P036+31 & 3 & 1.00 \\
+300517.5 & $\pm$0.0$\arcsec$ & $\pm$0.0$\arcsec$ & $\pm$0.10 & $\pm$0.53 & $\pm$0.1 & $\pm$0.1 & $\pm$0.1 & $\pm$0.1 & $\pm$10 \\
ILTJ144426.07 & 221.1086$^\circ$ & 36.7295$^\circ$ & 0.62 & 0.79 & 7.1 & 6.5 & 3.9 & 2.4 & 161 & 0.11 & S & P219+37 & 3 & 0.00 \\
+364346.3 & $\pm$0.5$\arcsec$ & $\pm$0.6$\arcsec$ & $\pm$0.11 & $\pm$0.23 & $\pm$1.3 & $\pm$1.1 & $\pm$1.3 & $\pm$1.1 & $\pm$80 \\
ILTJ143748.86 & 219.4536$^\circ$ & 36.7022$^\circ$ & 2.21 & 2.93 & 7.1 & 6.7 & 3.8 & 3.0 & 170 & 0.07 & S & P219+37 & 3 & 1.00 \\
+364207.9 & $\pm$0.1$\arcsec$ & $\pm$0.1$\arcsec$ & $\pm$0.08 & $\pm$0.16 & $\pm$0.2 & $\pm$0.2 & $\pm$0.2 & $\pm$0.2 & $\pm$28 \\
ILTJ100259.85 & 150.7494$^\circ$ & 59.4202$^\circ$ & 0.66 & 0.98 & 7.4 & 7.2 & 4.4 & 4.1 & 90 & 0.06 & S & P150+60 & 4 & 0.81 \\
+592512.5 & $\pm$0.3$\arcsec$ & $\pm$0.3$\arcsec$ & $\pm$0.06 & $\pm$0.14 & $\pm$0.7 & $\pm$0.6 & $\pm$0.7 & $\pm$0.6 & $\pm$138 \\
ILTJ100138.17 & 150.4091$^\circ$ & 59.2853$^\circ$ & 0.61 & 0.92 & 7.7 & 7.0 & 4.9 & 3.5 & 177 & 0.06 & S & P150+60 & 3 & 0.86 \\
+591707.0 & $\pm$0.3$\arcsec$ & $\pm$0.3$\arcsec$ & $\pm$0.06 & $\pm$0.14 & $\pm$0.8 & $\pm$0.7 & $\pm$0.8 & $\pm$0.7 & $\pm$40 \\
ILTJ215336.49 & 328.4020$^\circ$ & 27.4076$^\circ$ & 0.95 & 1.45 & 8.2 & 6.7 & 5.6 & 3.0 & 64 & 0.15 & S & P330+28 & 2 & 0.75 \\
+272427.3 & $\pm$0.6$\arcsec$ & $\pm$0.5$\arcsec$ & $\pm$0.15 & $\pm$0.36 & $\pm$1.5 & $\pm$1.0 & $\pm$1.5 & $\pm$1.0 & $\pm$36 \\
ILTJ224657.98 & 341.7416$^\circ$ & 26.3063$^\circ$ & 0.25 & 1.93 & 18.3 & 15.3 & 17.3 & 14.1 & 25 & 0.10 & S & P341+26 & 2 & 0.00 \\
+261822.6 & $\pm$2.4$\arcsec$ & $\pm$2.7$\arcsec$ & $\pm$0.09 & $\pm$0.77 & $\pm$6.6 & $\pm$5.3 & $\pm$6.6 & $\pm$5.3 & $\pm$93 \\
ILTJ121006.34 & 182.5264$^\circ$ & 29.5820$^\circ$ & 17.91 & 69.08 & 30.0 & 8.0 & 29.4 & 5.3 & 85 & 0.11 & M & P183+30 & 3 & 1.00 \\
+293455.0 & $\pm$0.0$\arcsec$ & $\pm$0.2$\arcsec$ & $\pm$0.11 & $\pm$0.96 & $\pm$0.6 & $\pm$0.1 & $\pm$0.6 & $\pm$0.1 & $\pm$1 \\
ILTJ221407.92 & 333.5330$^\circ$ & 34.7886$^\circ$ & 8.90 & 15.92 & 9.1 & 7.1 & 6.8 & 3.7 & 97 & 0.10 & S & P334+36 & 2 & 1.00 \\
+344719.0 & $\pm$0.0$\arcsec$ & $\pm$0.0$\arcsec$ & $\pm$0.10 & $\pm$0.27 & $\pm$0.1 & $\pm$0.1 & $\pm$0.1 & $\pm$0.1 & $\pm$2 \\
ILTJ083500.48 & 128.7520$^\circ$ & 54.4843$^\circ$ & 0.74 & 2.31 & 12.3 & 9.1 & 10.8 & 6.9 & 50 & 0.12 & S & P128+54 & 5 & 0.62 \\
+542903.3 & $\pm$0.8$\arcsec$ & $\pm$0.7$\arcsec$ & $\pm$0.12 & $\pm$0.48 & $\pm$2.2 & $\pm$1.4 & $\pm$2.2 & $\pm$1.4 & $\pm$27 \\
ILTJ113243.58 & 173.1816$^\circ$ & 51.8272$^\circ$ & 0.54 & 0.57 & 7.0 & 5.5 & 0.0 & 0.0 & 83 & 0.07 & S & P12Hetdex11 & 4 & 0.00 \\
+514938.0 & $\pm$0.4$\arcsec$ & $\pm$0.3$\arcsec$ & $\pm$0.07 & $\pm$0.13 & $\pm$1.1 & $\pm$0.7 & $\pm$1.1 & $\pm$0.7 & $\pm$27 \\
\hline
\end{tabular}
\end{sidewaystable*}

\section{Future prospects}
\label{sec:future_prospects}

There are still significant technical challenges to address as we build from LoTSS-DR2 to a complete high quality northern hemisphere survey. Furthermore, there is substantial auxiliary information that can be added to the LoTSS-DR2 catalogues themselves to greatly enrich their scientific value. Several avenues we are currently pursuing are outlined below.